BIOCHEMISTRY, BIOMEDICINE & PHARMACEUTICS

Enteric bacteria/ Gut flora -  E. coli, Salmonella spp, and Shigella spp 1) A large family of enteric bacteria is present as normal flora in the intestines of humans and other mammals. Which of the following is less likely to be found as the normal flora of the intestine?   a) Escherichia spp b) Salmonella spp c) Staphylococcus spp d) Proteus spp 2) Which of the following bacteria is not a clinically important enterobacteriaceae? a) E.coli b) Streptococcus  pyogenes c) Salmonella typhi d) Proteus mirabilis 3) All are the important general characteristics of enteric bacteria, EXCEPT ? a) Aerobic and facultatively anaerobic b) Non-spore forming c) Grow in media with bile salts d) Do not produce nitrates e) Ferment glucose f) Most of them are catalase positive and oxidase negative 4) Enteric bacteria are mainly classified based on their ability to ferment various sugars including lactose.  Which of the following bacteria is a non-lactose fermen...

Key aspects of Bacterial pathogenesis/ General steps in bacterial pathogenesis Adherence and Colonization  Invasion Immune Evasion Toxin Production Nutrient Acquisition Host Cell Manipulation Inflammation and Tissue Damage                         Multiple Choice Questions on Bacterial Pathogenesis       Figure 1: Phagocyte activity and possible outcomes of phagocyte-bacterial interactions                                     (Source/Reference: Bailey & Scott’s Diagnostic  Microbiology) 1) Which of the following microorganism is the major inhabitant of the human skin? a) Escherichia coli b) Staphylococcus epidermidis c) Staphylococcus aureus d) Streptococcus pyogenes 2) Select all the medically important bacteria which are frequently isolated pathogen  human infections? a) Enteric ba...

                                                       Multiple Choice Questions on Neisseria species (Gram-negative cocci) 1) A 19-year-old female college freshman, presented to the university health center with a severe headache, fever, and a stiff neck. She lived in a dormitory and was active in various social activities. She had received all her childhood vaccinations but had not received a booster for the meningococcal vaccine recommended before college entry. Clinical Presentation: On day 1, the patient experienced a sudden onset of fever (39.5°C or 103.1°F), severe headache, nausea, and vomiting. She also noticed a rash on her trunk and legs. Over the next two days, her symptoms deteriorated further, leading to photophobia and altered mental status. Concerned, her roommates brought her to the university health center. Physical Examinati...

           Notes on Salmonella - Enteric or Typhoid fever, the diagnosis, treatment, and prevention               of  Typhoid        Salmonella:  Salmonella bacteria typically live in the intestines of animals and humans and are usually transmitted to humans through contaminated food or water. Main types of Salmonella associated with human infections are Salmonella enterica serotype Typhi (S. Typhi)   and Salmonella serotypes Paratyphi A, B, or C typhi  that cause typhoid fever and paratyphoid fever respectively. Salmonella are found as a gut flora / normal flora in many vertebrate species.  The bacteria are often associated with contaminated food, particularly undercooked or raw eggs, poultry, meat, and unpasteurized dairy products.  Common symptoms of a Salmonella infection include diarrhea, abdominal cramps, fever, nausea, and vomiting. These symptoms c...

                                                    Multiple Choice Question on Haemophilus spp (with a clinical case) 1) Which of these small, gram-negative coccobacillus are clinically important human pathogens? a) Haemophilus influenzae b) Bordetella pertussis c) Haemophilus parainfluenzae d) Streptococcus pyogenes e) Brucella melitensis 2) Why should specimens suspected of containing Haemophilus spp.be inoculated to appropriate media immediately? a) Because Haemophilus spp. are resistant to drying b) Because  Haemophilus  spp. are susceptible to drying c) Because  Haemophilus  spp. grow better at room temperature d) Because  Haemophilus  spp. do not require media for cultivation 3) Which of the following gram-negative coccobacillus require both the X ( hemin ) and V ( NAD ) factors for its growth? a) ...

    MCQs on biochemical tests reaction of Enterobacteriaceae family (gram negative bacteria)  1.Which biochemical test assesses the ability of bacteria to ferment lactose, sucrose, and glucose, as well as produce gas and hydrogen sulfide? a) Indole Test b) Methyl Red Test c) Voges-Proskauer Test d) Triple Sugar Iron Agar (TSI) Test 2.The production of red color after the addition of the MR indicator indicates a positive result for which of the following test? a) Citrate Utilization Test b) Indole Test c) Methyl Red Test d) Urease Test 3.Which of the following is a non lactose fermenter gram negative bacteria? a) Escherichia coli b)  Enterobacter aerogenes c) Klebsiella pneumoniae d) Salmonella typhi      4. Blackening of the medium in the Sulfur Indole Motility (SIM) Test indicates: a) Citrate utilization b) Hydrogen sulfide (H2S) production c) Indole production d) Motility 5.The ability of bacteria to hydrolyze urea to produce ammonia and carbon ...

Multiple Choice Questions on Yersinia pestis, Pasteurella sps- Plague 1) All of the following bacterial pathogens given below are the example of bacterial zoonotic diseases, EXCEPT a) Bacillus anthracis b) Borrelia burgdorferi c) Yersinia pestis d) Leishmania tropica 2) Which of the following is the most common form of plague that causes swelling of the lymph nodes? a) Septicemic plague b) Bubonic plague c) Pneumonic plague d) All of the above 3) Which of the following statements is NOT correct about the cultural characteristics of Yersinia pestis ? a) The bacteria can cause pneumonia in humans through airborne droplets  b) The suitable bacterial growth temperature is room temperature using MacConkey agar c) The bacteria is lactose positive d) The common source of transmission to humans is through rats  4) Select all the correct answers, the commonly used preventive measures to control the plague are ................................................? a) ...

                                                  MCQs and answers on Spirochetes 1) Which of the following is not the common morphological characteristics of spirochetes? a) They are gram-negative helical bacteria b) They are motile and have periplasmic flagella ( endo flagella ) c) They reproduce by transverse binary fusion d) They are obligate aerobes 2) Which of the following subspecies of Treponema pallidum causes endemic syphilis? a) Treponema carateum b) Treponema endemicum c) Treponema pertenue d) None of the above 3) The RPR   test  ( Rapid Plasma Reagin test ) is a nontreponemal test method that is a common screening test for syphilis, which of the following statement correctly describes the test? a) A screening test used for the detection of syphilis antibodies in the urine b) A screening test used for the detection of syp...